How on earth does that make sense? Amazon has data centers all over the world - why would working on a 2am page be any more efficient at the "office at location A" (corporate) versus the "office at location B" (home).
It doesn't make sense to me either. I believe at the time they said something about having a strict network access policy, forbidding access from home.
That's deeply not true for at least 10 years. Amazon has worldwide coverage for oncall rotations, and VPN for access from home or anywhere with a cell connection